One form of contraception involves the occlusion of reproductive tracts, particularly, the fallopian tubes in female subjects and the vas deferens in male subjects, with an embolic material and/or occluding device that acutely and/or chronically (following foreign body tissue reaction or epithelialization) blocks passage of sperm through the reproductive tract. Particular forms of occluding devices and systems and methods of inserting the occluding devices in the vas deferens or fallopian tubes are described in commonly owned U.S. Pat. Nos. 6,096,052 and 6,432,116 and in commonly assigned U.S Patent Application Publication Nos. 2001/0041900, 2005/0045183, 2005/0085844, 2005/0192616, 2005/0209633, and 2006/0009798, for example, certain features of which are embodied in the Ovion® permanent contraceptive system sold by the assignee of the present invention.
It would be desirable to provide contraceptive occlusion systems that provide improved delivery and deployment systems, implant structures, and the effectiveness of occlusion.